Pbocess fob the manufacture of wood alcohol



UNITED STATES PATENT OFFICE.

LEE 1. HAWLEY, OF MADISON, WISCONSIN.

No Drawing.

Specification of Letters Patent.

Patented Dec. 28, 1920.

Application filed October 19, 1920. Serial No. 418,103.

(FILED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. L, 625.)

To all whom it may concern:

Be it known that I, LEE F. HAWLEY, a citizen of the United States, and an employee of the Department of Agriculture of the United States of America, residing at Madison, in the county of Dane and State of Wisconsin, (whose post-oflice address is care of Forest Product Laboratory, Department of Agriculture, Madison, Wisconsin,) have invented a new and useful Process for the Manufacture of Wood Alcohol, of which the following is a specification.

This application is made under the act of March 3, 1883, chapter 143 (22 Stat. 625) and the invention herein described and claimed is hereby dedicated to the free use of the Government and the public without payment to me of any royalty thereon.

This invention relates to a process of the manufacture of wood alcohol by means of the addition of sodium carbonate to wood prior to distillation in order that maximum yields of alcohol may be obtained upon distillation.

It has been found that the addition of sodium carbonate to wood previous to distillation increases the yield of wood alcohol obtained. For instance quantities of sodium carbonate varying from 10 per cent. to 1 per cent. of the dry weight of the wood all give increased yields of alcohol. There are four reasons, however, why these larger quantities are not advisable: (1) There is an apparent excess heat of reaction which causes the distillation to run away and superheating and loss of alcohol results. (2) The yield of acetic'acid is decreased. (3) The cost of the treatment is greater. l) The amount of ashleft in the charcoal is greater. In the case of one per cent. Na cO the maximum yield of alcohol is obtained without serious superheating and the cost of the treatment is very low. Also the eflect of the Na CO on the ash content of the charcoal is not so great and the yield of acetic acid is not decreased.

In the practice of my invention the Na CO is added to the wood in any suitable manner, butit should be evenly distributed throughout the mass of the wood; f In the case of sawdust or other such finely divided wood a simple process, of sprinkling the wood in thin layers or mixing the dust with a suitable quantity of solution of the proper concentration, but in the case of larger sized pieces of wood such as blocks or large chips a pressure impregnation process might be required. Large sticks of cordwood such as are commonly used for wood distillation would probably be unsuitable even for treatment by a pressure process.

The method of distillation to be used in the treated wood is not of great importance so long. as it is suitable for the size of wood distilled; for instance sawdust would require a special process and apparatus such as a rotating retort or a briqueting process. In distilling the treated wood it is as desirable to practice careful temperature control as when distilling untreated wood, perhaps even more desirable because the presence of the chemical seems to increase the heat of reaction and make control more difficult.

I claim:

1. The process of manufacturing wood alcohol by treating wood with sodium car bonate and destructively distilling the treated wood by any of the well known methods for the production of methyl alcohol and acetic acid.

2. The process of manufacturing wood alcohol consisting in sprinkling dry sawdust with water containing in solution sodium carbonate, drying the treated sawdust, briqueting the dried sawdust and destructively distilling the briquets.

3. The process of wood distillation which consists in preparing a thorough and intimate mixture of the wood with sodium carbonate in the proportion of 20 pounds of l Ta .,CO per ton of wood and destructively distilling the mixture under conditions suitable for the production of wood alcohol and acetic acid.

4. The process of wood distillation which consists in treating blocks about five inches long with the grain with a water solution of sodium carbonate under pressure and with a concentration of the solution so that about one per cent. sodium carbonate is left in the wood, and destructively distilling the treated blocks.

' F. HAWLEY, 

